Tuesday, June 05, 2018

SpaceX Starlink test -- good news but unanswered questions

Last week, Elon Musk was asked on Twitter how the Starlink tests were going and he replied that the two test satellites, TinTin A and B, are connecting at "high bandwidth" with 25 ms latency.

That's good news but it leaves a lot unanswered. For example, he did not mention the speed and reliability of the phased-array handoffs between the satellites and ground terminals and he said nothing about tests of the inter-satellite laser links.

While we have experience with radio links between satellites and the ground, inter-satellite laser links are new so I'm more curious about those tests. What sorts of speeds and latencies are they seeing on transmissions between TinTin A and B and how well are they doing at creating and maintaining links between the satellites? Fast inter-satellite switching and transmission speed are critical to overall performance of the constellation grid, particularly on long-distance links.

Click here for a survey and updated progress report on SpaceX Starlink and other potential LEO-satellite based Internet service providers.